The present invention relates to artificial leather useful as automobile interior materials and interior materials such as upholsteries. Particularly, the invention relates to stretchable artificial leather having good visual quality, seam fatigue properties and sitting comfortability even in the case of using the stretchable artificial leather in products having complicated three-dimensional shape.
In general, artificial leather used as automobile interior materials and interior materials such as upholsteries comprises a resin layer and a fibrous substrate. Non-woven fabric and woven fabric are preferably used in the fibrous substrate for the reason that those fabrics have excellent processability and dimensional stability. The non-woven fabric and woven fabric have excellent dimensional stability, but have poor stretchability. Therefore, in the case that those fabrics are used in products having complicated three-dimensional shape, those fabrics had the problem that because of poor follow-up properties to a shape, wrinkles are generated when setting up those fabrics on products, resulting in poor visual quality.
Artificial leather using weft knitted fabric as a fibrous substrate is disclosed to overcome the above problems.
For Example, Japanese Unexamined Patent Publication JP-A 9-31862 (1997) discloses artificial leather comprising weft knitted fabric having a both surface-knitted texture, as a fibrous substrate, and a polyurethane resin skin layer comprising a silicone-modified non-yellowing polycarbonate polyurethane resin, laminated to the surface of the fibrous substrate through a polyurethane resin adhesive layer, the artificial leather having excellent molding processability and shapeability in addition to various properties such as light resistance, hydrolysis resistance, heat deterioration resistance, abrasion resistance and oleic acid resistance. JP-A 9-111671 (1997) discloses artificial leather comprising a base fabric having laminated on the surface thereof a urethane adhesive layer and a polyurethane skin layer in this order, wherein the base fabric is a knit fabric having raising on the surface thereof and is a knit fabric having been subjected to specific knitting through a spun yarn as a weft in a course direction of the knit fabric, the base fabric has an elongation of from 60 to 100% in longitudinal and lateral directions, and 20 to 99% of the length of the raising fiber are present in the adhesive layer. The artificial leather is free of fraying and has excellent durability, tear strength, feeling and processability along design. JP-A 2001-164477 discloses artificial leather comprising a raised circular knit fabric having laminated on a raised face side thereof a polyurethane adhesive layer and a polyurethane skin layer in this order, wherein the raised circular knit fabric comprises a ground yarn and a raised yarn, each comprising a polyester multifilament, a ratio of the fed length of the ground yarn and that of the raised yarn is from 1:1.1 to 1:1.3, and a ratio of the number of knitted loops of the ground yarn and that of the raised yarn is 1:1. The artificial leather has excellent stretchability, feeling, peel strength and tear strength.
However, in the case of using the weft knitted fabric as a fibrous substrate as disclosed in the above documents, stretchability is improved as compared with non-woven fabric and woven fabric, but knitted loop is easily opened in the weft knitted fabric. As a result, in the case of using the weft knitted fabric in products having complicated three-dimensional shape, there is the problem that pinholes are highly visible when setting up, resulting in deterioration of visual quality, and there is also the problem that durability, particularly seam fatigue properties, is poor.